MEXICO CITY – A year after his bitter defeat in Mexico's presidential election, leftist Andrés Manuel López Obrador showed his political strength yesterday by summoning supporters to a rally and asking them to join him in a peaceful revolution to transform the country.

As a throng of more than 200,000 chanted, “Presidente! Presidente!” López Obrador set a goal and a deadline for his grass-roots movement: 5 million people by the end of next year.

“I am optimistic; I am certain that we are going to change this country without violence,” he said to the crowd in Mexico City's Zocalo, a colonial plaza he described as “the political heart of the country.”

The day was laden with symbolism.

López Obrador called his supporters to the streets the day before the one-year anniversary of his loss to Felipe Calderón – a defeat López Obrador blames on fraud. López Obrador also timed the release of his book, “The Mafia Robbed Us of the Presidency,” to coincide with the rally.

He labeled himself Mexico's “legitimate president” and firmly told his audience: “We won the presidential election. There is no doubt about that.

“But one year after the presidential election we can proudly say: 'Here we are. Here we will continue,' ” he said. “Sooner or later, our cause will triumph. We will make Mexico a truly democratic country.”

The rally was seen as a critical test of López Obrador's ability to turn out the masses after losing to Calderón by 233,831 votes out of 41 million cast in the closest presidential election in Mexico's history.

As the Zocalo filled with people from all walks of life – lawyers and peasant farmers, psychologists and homemakers – it was clear that López Obrador still has a following in this impoverished country.

“He has gained moral authority because he is firm in his democratic convictions,” said attorney Jesús González, 63. “Calderón is a demagogue. He does not have any scruples about doing whatever it takes to achieve his personal ambitions. His government has been a resounding failure.”

Despite López Obrador's unpopular protests last year that paralyzed Mexico City, 61 percent of Mexicans who cast their ballots for him said they would vote for him again if the election were held today, according to a poll published yesterday in the Mexico City daily Reforma.

That finding indicates that López Obrador has the support of about 9 million people.

“The fact that he can still bring people into the streets makes him a player,” said George Grayson, a Mexico scholar at the College of William & Mary who attended yesterday's rally.

Since losing his legal challenge in September, López Obrador has gotten married, had a son and published his book berating a political system that he alleges conspired to deny him the presidency.

López Obrador also launched a nationwide tour of rural towns and cities. At each stop, he signs up people as representatives of his parallel government, a tactic similar to one used by leaders of the Mexican Revolution.

He has already visited 530 towns. During the next year, López Obrador plans to visit almost 2,000 more municipalities in an effort to enlist millions in his cause.

As he tours the country, López Obrador is stoking the fire of discontent among the nation's poor and reminding them of the injustices in Mexico, political analysts said.

“López Obrador is the messiah in waiting,” Grayson said. “Mexicans living in poverty haven't seen the benefits of the Calderón government. They know López Obrador represents a clear option to the establishment. His hope is that Felipe Calderón will fall on his face, that the economy will deteriorate, and when that happens he'll be ready to offer himself to the people in 2012.”